High-resolution photographs in the rocket ultraviolet of the Orion Nebula
Abstract
High-resolution photographs of the Orion Nebula have been obtained in UV bands centered near 1400, 1820, 2240 and 2620 by a 31-cm telescope mounted on an Astrobee sounding rocket. Reduction of the data by image processing, photometric calibration and error analysis steps was used to derive a matrix of values of specific intensity in absolute units. Data indicate that the Orion Nebula is primarily a reflection nebula in the UV, so that morphology is determined by the distribution of dust with respect to the illuminating stars. Ultraviolet color gradients for each color relative to the 1820-A image indicate reddening towards the outer parts of the nebula, as well as fairly symmetric dust scattering in the Theta 1 and Theta 2 Ori region. The color gradients also imply a monotonic change in scattering phase function asymmetry between 2620 and 1400 A. Total nebular flux in each bandpass is observed to be about 2.5 times the stellar flux from the Trapezium, indicating a high scattering efficiency.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- April 1982
- DOI:
- 10.1086/159806
- Bibcode:
- 1982ApJ...255...87B
- Keywords:
-
- Astronomical Photography;
- High Resolution;
- Image Processing;
- Orion Nebula;
- Rocket Sounding;
- Ultraviolet Radiation;
- Calibrating;
- Data Reduction;
- Error Analysis;
- Optical Thickness;
- Astronomy